At least there is a measurable neutrality about today's Heineken Cup semi-final between Clermont Auvergne and the defending champions, Leinster. The Stade Chaban-Delmas in Bordeaux, formerly the Stade du Parc Lescure, where Bath beat Brive in the 1998 final, is 200 miles from Clermont-Ferrand and every centimetre away from the Massif Central is half an inch closer to a more familiar seaboard scene for the Irish. Clermont Auvergne do not lose in the mountain fortress they call home, the Stade Marcel Michelin, their unbeaten record there stretching to 41 games.

Clermont fans may still be expected to outnumber travelling Leinster supporters 10 to one, but at least the neutral stadium, named after Jacques Chaban-Delmas, the Gaullist prime minister who served under president Georges Pompidou and who was mayor of Bordeaux, does not offer the volcanic eruption of the Michelin at full bore. Which is another lucky break for the Irish province, since their two "neutral" semis in Ireland, in their winning years of 2009 against Munster and 2011 against Toulouse, were played at Croke Park and the Aviva Stadium. I suppose if they'd been staged in Baggot Street they could have been closer to the heart of Dublin, but not by much.

Leinster, then, have less of a disadvantage on their travels, and in a clash of the two most complete teams in Europe such a cushioned discomfort may be important. This promises to be a serious test of nerve, with no performer tested more than the referee, Wayne Barnes.

There will be some mean scrummaging to supervise, for example. If Leinster celebrated the return of one of the most famous names in the game, Brian O'Driscoll, for the quarter final against the Cardiff Blues and if the centre could sit tight and admire the damage inflicted by the front five of Cian Healy, Richardt Strauss, Mike Ross, Leo Cullen and Brad Thorn – the venerable New Zealand second row enjoying a late cameo in Europe – then Clermont have welcomed back a less well-known name.

The tight-head prop Davit Zirakashvili is one of the many Georgians bringing their wrestling traditions and skills into the front rows of French rugby. Zirakashvili is the most fearsome, a burly 28-year old who broke his arm against Leicester in December but who is now back, returning with a vengeance earlier this month to make a real mess of Perpignan, who are not exactly indifferent to the joys of scrummaging themselves.

The more the tortured strains of "Crouch, touch … [I suspect you know the rest of the dirge by now]" threaten to ruin the game, the more important the set piece becomes in these finely balanced end-of-season encounters. This is the test for Barnes: to reward the better scrummagers even if it means allowing their work to stray over what the higher authorities deem to be the lines of health and safety.

Healy may pass the Georgian test with not a peep required from the ref, and that would certainly put Leinster in the driving seat. Clermont have never been in a semi before; this is the Irish team's fourth in succession. In the balance of the margins, vocal support from the French stands may not stifle the on-field experience of the Irish.

Clermont, however, burst over a threshold in 2010, winning the French championship for the first time in 11 attempts and after losing the three previous finals. It did nothing but increase their lust for more and they are in full flow on two fronts, their domestic Top 14 and the Heineken Cup. The way they disposed of Saracens in Watford in the quarter-final at the beginning of this month emphasised their power and discipline.

The ability to blend fury and control comes from their coach, the New Zealander Vern Cotter, who had a fellow countryman as his assistant in the breakthrough campaign of 2009-10. Joe Schmidt is now the head coach of Leinster, and their battle of wills is just one of Sunday's many head-to-heads. From the coaches to the full-backs, Lee Byrne with Clermont against Rob Kearney, and all the way through the teams to the Healy-Zirakashvili confrontation up front, this is a little bit out of the ordinary.

Sometimes, the very fact of a match being so finely balanced militates against a spectacle, as the players' similarity of standard – high across the board – means that nothing escapes their grasp. Or perhaps the peerless O'Driscoll may have one last trick to perform on a neutral piece of France.